A MNDO SCF-MO theoretical study of the mechanism of [1,2] migrations in free radicals as a model for coenzyme B12 mediated rearrangement reactions

Abstract

MNDO SCF-MO calculations predict that [1,2] radical migrations that are that are thought to occur in coenzyme B₁₂ mediated rearrangements can proceed by three distinct mechanistic pathways:–CH(NH₂)Co₂H by dissociation–recombination in 1,2 diols by stepwise migration of a protonated OH group via an intermediate π-allyl compelx, and acyl groups by either a concerted migration or dissociation recombination; X = SiH₃, CHO, CN, and CS₂H are predicted to be good migrating groups in such reactions.